Olefinic metathesis in the presence of phenolic compounds

Example 1

The Phenol Enhancement Effect

[0066] The general experimental procedure was followed without addition of any phenol and with the addition of 500 eq of phenol.

[0067] An increased conversion of 1-octene to the desired 7-tetradecene product was observed for the metathesis of 1-octene when 500 equivalents of phenol was added to the reaction mixture (Table 1) compared to the reaction where no phenol was added. Under these conditions, no detectable (by GC) amounts of isomerised octene or secondary metathesis products (SMP's) were observed. Furthermore, the catalyst was active even after four hours, in marked contrast to the control experiment where no phenol was added. In an effort to verify the results obtained above, the reaction was repeated. These results indicate that the reaction can be readily reproduced. TABLE 1 Metathesis of 1-octene with G1 (no phenol) vs G1 + phenol (500 eq) at 50° C. Molar % Conversion of 1-Octene Conditions After 3 h G1 with no phenol added 26.5% G1 + 500 eq phenol 82.0% G1 + 500 eq phenol (repeated) 86.6%

[0068] FIG. 1 below shows an improved reaction rate where G1 is used in combination with phenol compared to where G1 without phenol is used.

Example 2

Effect of Phenol Concentration

[0069] The 1-octene metathesis reactions were performed following the general experimental procedure and using 200, 500 and 1000 equivalents of phenol, respectively. The results are shown in Table 2. Under these conditions, optimum performance is achievable with either 500 or 1000 equivalents of phenol. TABLE 2 Metathesis of 1-octene with G1 + phenol (200, 500 and 1000eq). Molar % Conversion of 1-Octene Conditions After 3 h G1 with no phenol added 26% G1 + 200 eq phenol 63% G1 + 500 eq phenol 82% G1 + 1000 eq phenol 77%

Example 3

Effect of Substitution on Phenol

[0070] In an effort to asses the effect of substitution on the benzene ring of the phenol on the formation of 7-tetradecene in 1-octene metathesis, 500 equivalents of compounds 1-6 were added to the reaction mixture, following the general experimental procedure. The results are summarized in Table 3. TABLE 3 Metathesis of 1-octene with substituted phenols Molar % Conversion of 1- Conditions Octene After 3 h G1 with no phenol added 26.5% G1 + 500 eq 4-Cl-phenol (Compound 3) 58.2% G1 + 500 eq 4-CF3-phenol (Compound 4) 64.8% G1 + 500 eq 4-I-phenol (Compound 5) 71.0% G1 + 500 eq 4-OMe-phenol (Compound 1) 71.8% G1 + 500 eq phenol 82.0% G1 + 500 eq 4-F-phenol (Compound 6) 86.0% G1 + 500 eq 4-Me-phenol (cresol) 91.1% (Compound 2)

[0071] These results show that the addition of 500 equivalents of p-cresol (compound 2) afforded very similar (but slightly better) yields compared to those obtained with phenol. 4-Methoxyphenol (compound 1) gave slightly lower conversions than phenol and p-cresol, Electron-withdrawing groups and electronegative substituents present on the phenol moiety (compounds 3-5) gave lower conversions compared with those results obtained with phenol, but still better than the control without phenol. Compound 6 also has electronegative substituents but gave better results than phenol.

[0072] Other additives were also tested, namely BHT (2,6 di-tert-butyl-4-methyl phenol)naphthols, hydroquinone and catechol while following the general experimental procedure. Results are shown in Table 4. TABLE 4 Metathesis of 1-octene with other phenols. Molar % Conversion of 1-Octene Conditions After 3 h G1 with no phenol added 27% G1 + 500 eq hydroquinone 55% G1 + 500 eq 2-napthol 65% G1 + 500 eq catechol 76% G1 + 500 eq 4-1-napthol 77% G1 + 500 eq BHT 79% G1 + 500 eq phenol 82%

[0073] The results show that the conversion of 1-octene to 7-tetradecene is increased by the addition of BHT, napthols, hydroquinone and catechol relative to the control G1 metathesis experiment using G1 with no phenol added.